js/ndnProtocol/components/ndnProtocolService.js - ndn-js - Gitiles

 /*
  * @author: Jeff Thompson
  * See COPYING for copyright and distribution information.
  * This is the ndn protocol handler.
  * Protocol handling code derived from http://mike.kaply.com/2011/01/18/writing-a-firefox-protocol-handler/
  */

 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cr = Components.results;

 const nsIProtocolHandler = Ci.nsIProtocolHandler;

 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 Components.utils.import("chrome://modules/content/ndn-js.jsm");
 Components.utils.import("chrome://modules/content/ContentChannel.jsm");

 function NdnProtocol() {
 }

 NdnProtocol.prototype = {
     scheme: "ndn",
     protocolFlags: nsIProtocolHandler.URI_NORELATIVE |
                    nsIProtocolHandler.URI_NOAUTH |
                    nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,
     transport: new XpcomTransport(),

     newURI: function(aSpec, aOriginCharset, aBaseURI)
     {
         // We have to trim now because nsIURI converts spaces to %20 and we can't trim in newChannel.
         var spec = aSpec.trim();
         var preSearch = spec.split('?', 1)[0];
         var searchAndHash = spec.substr(preSearch.length).trim();

         var uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
         uri.spec = preSearch.trim() + searchAndHash;
         return uri;
     },

     newChannel: function(aURI)
     {
         var thisNdnProtocol = this;

         try {
             // Decode manually since nsIURI doesn't have selectors for hash, etc.
             var spec = aURI.spec.trim();
             var preHash = spec.split('#', 1)[0];
             var hash = spec.substr(preHash.length).trim();
             var preSearch = preHash.split('?', 1)[0];
             var search = preHash.substr(preSearch.length).trim();
             // Set nameString to the preSearch without the protocol.
             var nameString = preSearch.trim();
             if (nameString.indexOf(':') >= 0)
                 nameString = nameString.substr(nameString.indexOf(':') + 1).trim();

             var template = new Interest(new Name([]));
             // Use the same default as NDN.expressInterest.
             template.interestLifetime = 4200;
             var searchWithoutNdn = extractNdnSearch(search, template);

             var requestContent = function(contentListener) {
                 var name = new Name(nameString);
                 // TODO: Strip off an ending implicit digest before checking the last component?
                 var uriEndsWithSegmentNumber = endsWithSegmentNumber(name);

                 var ndn = new NDN({ host: "lioncub.metwi.ucla.edu", port: 9695,
                       // Use the same transport object each time.
                       getTransport: function() { return thisNdnProtocol.transport; } });
                 ndn.expressInterest(name,
                     new ContentClosure(ndn, contentListener, uriEndsWithSegmentNumber,
                             aURI.originCharset, searchWithoutNdn + hash),
                     template);
             };

             return new ContentChannel(aURI, requestContent);
         } catch (ex) {
             dump("NdnProtocol.newChannel exception: " + ex + "\n" + ex.stack);
         }
     },

     classDescription: "ndn Protocol Handler",
     contractID: "@mozilla.org/network/protocol;1?name=" + "ndn",
     classID: Components.ID('{8122e660-1012-11e2-892e-0800200c9a66}'),
     QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler])
 }

 if (XPCOMUtils.generateNSGetFactory)
     var NSGetFactory = XPCOMUtils.generateNSGetFactory([NdnProtocol]);
 else
     var NSGetModule = XPCOMUtils.generateNSGetModule([NdnProtocol]);

 /*
  * Create a closure for calling expressInterest.
  * contentListener is from the call to requestContent.
  * uriEndsWithSegmentNumber is true if the URI passed to newChannel has a segment number
  *    (used to determine whether to request only that segment number and for updating the URL bar).
  * uriOriginCharset is the charset of the URI passed to newChannel (used for making a new URI)
  * uriSearchAndHash is the search and hash part of the URI passed to newChannel, including the '?'
  *    and/or '#' but without the interest selector fields.
  */
 var ContentClosure = function ContentClosure
         (ndn, contentListener, uriEndsWithSegmentNumber, uriOriginCharset, uriSearchAndHash) {
     // Inherit from Closure.
     Closure.call(this);

     this.ndn = ndn;
     this.contentListener = contentListener;
     this.uriEndsWithSegmentNumber = uriEndsWithSegmentNumber;
     this.uriOriginCharset = uriOriginCharset;
     this.uriSearchAndHash = uriSearchAndHash;

     this.firstReceivedSegmentNumber = null;
     this.firstReceivedContentObject = null;
     this.contentSha256 = null;
 }

 ContentClosure.prototype.upcall = function(kind, upcallInfo) {
     if (!(kind == Closure.UPCALL_CONTENT ||
           kind == Closure.UPCALL_CONTENT_UNVERIFIED))
         // The upcall is not for us.
         return Closure.RESULT_ERR;

     var contentObject = upcallInfo.contentObject;
     if (contentObject.content == null) {
         dump("NdnProtocol.ContentClosure: contentObject.content is null\n");
         return Closure.RESULT_ERR;
     }

     // If !this.uriEndsWithSegmentNumber, we use the segmentNumber to load multiple segments.
     var segmentNumber = null;
     if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
         segmentNumber = DataUtils.bigEndianToUnsignedInt
             (contentObject.name.components[contentObject.name.components.length - 1]);
         if (this.firstReceivedSegmentNumber == null) {
             // This is the first call.
             this.firstReceivedSegmentNumber = segmentNumber;
             if (segmentNumber != 0) {
                 // Special case: Save this content object for later and request segment zero.
                 this.firstReceivedContentObject = contentObject;
                 var componentsForZero = contentObject.name.components.slice
                     (0, contentObject.name.components.length - 1);
                 componentsForZero.push([0]);
                 this.ndn.expressInterest(new Name(componentsForZero), this);
                 return Closure.RESULT_OK;
             }
         }
     }

     if (this.uriEndsWithSegmentNumber || segmentNumber == null || segmentNumber == 0) {
         // This is the first or only segment, so start.
         // Get the URI from the ContentObject including the version.
         var contentUriSpec;
         if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
             var nameWithoutSegmentNumber = new Name
                 (contentObject.name.components.slice(0, contentObject.name.components.length - 1));
             contentUriSpec = "ndn:" + nameWithoutSegmentNumber.to_uri();
         }
         else
             contentUriSpec = "ndn:" + contentObject.name.to_uri();

         // Include the search and hash.
         contentUriSpec += this.uriSearchAndHash;

         var contentTypeEtc = getNameContentTypeAndCharset(contentObject.name);
         var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
         this.contentListener.onStart(contentTypeEtc.contentType, contentTypeEtc.contentCharset,
             ioService.newURI(contentUriSpec, this.uriOriginCharset, null));

         if (contentObject.name.getContentDigestValue() != null)
             // We need to compute the content digest.
             this.contentSha256 = new Sha256();
     }

     this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
     if (this.contentSha256 != null)
         this.contentSha256.update(contentObject.content);

     // Check for the special case if the saved content is for the next segment that we need.
     if (this.firstReceivedContentObject != null &&
         this.firstReceivedSegmentNumber == segmentNumber + 1) {
         // Substitute the saved contentObject send its content and keep going.
         contentObject = this.firstReceivedContentObject;
         segmentNumber = segmentNumber + 1;
         // Clear firstReceivedContentObject to save memory.
         this.firstReceivedContentObject = null;

         this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
         if (this.contentSha256 != null)
             this.contentSha256.update(contentObject.content);
     }

     var finalSegmentNumber = null;
     if (contentObject.signedInfo != null && contentObject.signedInfo.finalBlockID != null)
         finalSegmentNumber = DataUtils.bigEndianToUnsignedInt(contentObject.signedInfo.finalBlockID);

     if (!this.uriEndsWithSegmentNumber &&
         segmentNumber != null &&
         (finalSegmentNumber == null || segmentNumber != finalSegmentNumber)) {
         // Make a name for the next segment and get it.
         var segmentNumberPlus1 = DataUtils.nonNegativeIntToBigEndian(segmentNumber + 1);
         // Put a 0 byte in front.
         var nextSegmentNumber = new Uint8Array(segmentNumberPlus1.length + 1);
         nextSegmentNumber.set(segmentNumberPlus1, 1);

         var components = contentObject.name.components.slice
             (0, contentObject.name.components.length - 1);
         components.push(nextSegmentNumber);
         this.ndn.expressInterest(new Name(components), this);
     }
     else {
         // Finished.
         this.contentListener.onStop();
         if (this.contentSha256 != null) {
             var nameContentDigest = contentObject.name.getContentDigestValue();
             if (nameContentDigest != null &&
                 !DataUtils.arraysEqual(nameContentDigest, this.contentSha256.finalize()))
                 // TODO: How to show the user an error for invalid digest?
                 dump("Content does not match digest in name " + contentObject.name.to_uri());
         }
     }

     return Closure.RESULT_OK;
 };

 /*
  * Scan the name from the last component to the first (skipping special name components)
  *   for a recognized file name extension, and return an object with properties contentType and charset.
  */
 function getNameContentTypeAndCharset(name) {
     var iFileName = name.indexOfFileName();
     if (iFileName < 0)
         // Get the default mime type.
         return MimeTypes.getContentTypeAndCharset("");

     return MimeTypes.getContentTypeAndCharset
         (DataUtils.toString(name.components[iFileName]).toLowerCase());
 }

 /*
  * Return true if the last component in the name is a segment number..
  */
 function endsWithSegmentNumber(name) {
     return name.components != null && name.components.length >= 1 &&
         name.components[name.components.length - 1].length >= 1 &&
         name.components[name.components.length - 1][0] == 0;
 }

 /*
  * Find all search keys starting with "ndn." and set the attribute in template.
  * Return the search string including the starting "?" but with the "ndn." keys removed,
  *   or return "" if there are no search terms left.
  */
 function extractNdnSearch(search, template) {
     if (!(search.length >= 1 && search[0] == '?'))
         return search;

     var terms = search.substr(1).split('&');
     var i = 0;
     while (i < terms.length) {
         var keyValue = terms[i].split('=');
         var key = keyValue[0].trim();
         if (key.substr(0, 4) == "ndn.") {
             if (keyValue.length >= 1) {
                 var value = keyValue[1].trim();
                 var nonNegativeInt = parseInt(value);

                 if (key == "ndn.MinSuffixComponents" && nonNegativeInt >= 0)
                     template.minSuffixComponents = nonNegativeInt;
                 if (key == "ndn.MaxSuffixComponents" && nonNegativeInt >= 0)
                     template.maxSuffixComponents = nonNegativeInt;
                 if (key == "ndn.ChildSelector" && nonNegativeInt >= 0)
                     template.childSelector = nonNegativeInt;
                 if (key == "ndn.AnswerOriginKind" && nonNegativeInt >= 0)
                     template.answerOriginKind = nonNegativeInt;
                 if (key == "ndn.Scope" && nonNegativeInt >= 0)
                     template.scope = nonNegativeInt;
                 if (key == "ndn.InterestLifetime" && nonNegativeInt >= 0)
                     template.interestLifetime = nonNegativeInt;
                 if (key == "ndn.PublisherPublicKeyDigest" && nonNegativeInt >= 0)
                     template.publisherPublicKeyDigest = DataUtils.toNumbersFromString(unescape(value));
                 if (key == "ndn.Nonce" && nonNegativeInt >= 0)
                     template.nonce = DataUtils.toNumbersFromString(unescape(value));
                 // TODO: handle Exclude.
             }

             // Remove the "ndn." term and don't advance i.
             terms.splice(i, 1);
         }
         else
             ++i;
     }

     if (terms.length == 0)
         return "";
     else
         return "?" + terms.join('&');
 }
	/*
	* @author: Jeff Thompson
	* See COPYING for copyright and distribution information.
	* This is the ndn protocol handler.
	* Protocol handling code derived from http://mike.kaply.com/2011/01/18/writing-a-firefox-protocol-handler/
	*/

	const Cc = Components.classes;
	const Ci = Components.interfaces;
	const Cr = Components.results;

	const nsIProtocolHandler = Ci.nsIProtocolHandler;

	Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
	Components.utils.import("chrome://modules/content/ndn-js.jsm");
	Components.utils.import("chrome://modules/content/ContentChannel.jsm");

	function NdnProtocol() {
	}

	NdnProtocol.prototype = {
	scheme: "ndn",
	protocolFlags: nsIProtocolHandler.URI_NORELATIVE \|
	nsIProtocolHandler.URI_NOAUTH \|
	nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,
	transport: new XpcomTransport(),

	newURI: function(aSpec, aOriginCharset, aBaseURI)
	{
	// We have to trim now because nsIURI converts spaces to %20 and we can't trim in newChannel.
	var spec = aSpec.trim();
	var preSearch = spec.split('?', 1)[0];
	var searchAndHash = spec.substr(preSearch.length).trim();

	var uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
	uri.spec = preSearch.trim() + searchAndHash;
	return uri;
	},

	newChannel: function(aURI)
	{
	var thisNdnProtocol = this;

	try {
	// Decode manually since nsIURI doesn't have selectors for hash, etc.
	var spec = aURI.spec.trim();
	var preHash = spec.split('#', 1)[0];
	var hash = spec.substr(preHash.length).trim();
	var preSearch = preHash.split('?', 1)[0];
	var search = preHash.substr(preSearch.length).trim();
	// Set nameString to the preSearch without the protocol.
	var nameString = preSearch.trim();
	if (nameString.indexOf(':') >= 0)
	nameString = nameString.substr(nameString.indexOf(':') + 1).trim();

	var template = new Interest(new Name([]));
	// Use the same default as NDN.expressInterest.
	template.interestLifetime = 4200;
	var searchWithoutNdn = extractNdnSearch(search, template);

	var requestContent = function(contentListener) {
	var name = new Name(nameString);
	// TODO: Strip off an ending implicit digest before checking the last component?
	var uriEndsWithSegmentNumber = endsWithSegmentNumber(name);

	var ndn = new NDN({ host: "lioncub.metwi.ucla.edu", port: 9695,
	// Use the same transport object each time.
	getTransport: function() { return thisNdnProtocol.transport; } });
	ndn.expressInterest(name,
	new ContentClosure(ndn, contentListener, uriEndsWithSegmentNumber,
	aURI.originCharset, searchWithoutNdn + hash),
	template);
	};

	return new ContentChannel(aURI, requestContent);
	} catch (ex) {
	dump("NdnProtocol.newChannel exception: " + ex + "\n" + ex.stack);
	}
	},

	classDescription: "ndn Protocol Handler",
	contractID: "@mozilla.org/network/protocol;1?name=" + "ndn",
	classID: Components.ID('{8122e660-1012-11e2-892e-0800200c9a66}'),
	QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler])
	}

	if (XPCOMUtils.generateNSGetFactory)
	var NSGetFactory = XPCOMUtils.generateNSGetFactory([NdnProtocol]);
	else
	var NSGetModule = XPCOMUtils.generateNSGetModule([NdnProtocol]);

	/*
	* Create a closure for calling expressInterest.
	* contentListener is from the call to requestContent.
	* uriEndsWithSegmentNumber is true if the URI passed to newChannel has a segment number
	* (used to determine whether to request only that segment number and for updating the URL bar).
	* uriOriginCharset is the charset of the URI passed to newChannel (used for making a new URI)
	* uriSearchAndHash is the search and hash part of the URI passed to newChannel, including the '?'
	* and/or '#' but without the interest selector fields.
	*/
	var ContentClosure = function ContentClosure
	(ndn, contentListener, uriEndsWithSegmentNumber, uriOriginCharset, uriSearchAndHash) {
	// Inherit from Closure.
	Closure.call(this);

	this.ndn = ndn;
	this.contentListener = contentListener;
	this.uriEndsWithSegmentNumber = uriEndsWithSegmentNumber;
	this.uriOriginCharset = uriOriginCharset;
	this.uriSearchAndHash = uriSearchAndHash;

	this.firstReceivedSegmentNumber = null;
	this.firstReceivedContentObject = null;
	this.contentSha256 = null;
	}

	ContentClosure.prototype.upcall = function(kind, upcallInfo) {
	if (!(kind == Closure.UPCALL_CONTENT \|\|
	kind == Closure.UPCALL_CONTENT_UNVERIFIED))
	// The upcall is not for us.
	return Closure.RESULT_ERR;

	var contentObject = upcallInfo.contentObject;
	if (contentObject.content == null) {
	dump("NdnProtocol.ContentClosure: contentObject.content is null\n");
	return Closure.RESULT_ERR;
	}

	// If !this.uriEndsWithSegmentNumber, we use the segmentNumber to load multiple segments.
	var segmentNumber = null;
	if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
	segmentNumber = DataUtils.bigEndianToUnsignedInt
	(contentObject.name.components[contentObject.name.components.length - 1]);
	if (this.firstReceivedSegmentNumber == null) {
	// This is the first call.
	this.firstReceivedSegmentNumber = segmentNumber;
	if (segmentNumber != 0) {
	// Special case: Save this content object for later and request segment zero.
	this.firstReceivedContentObject = contentObject;
	var componentsForZero = contentObject.name.components.slice
	(0, contentObject.name.components.length - 1);
	componentsForZero.push([0]);
	this.ndn.expressInterest(new Name(componentsForZero), this);
	return Closure.RESULT_OK;
	}
	}
	}

	if (this.uriEndsWithSegmentNumber \|\| segmentNumber == null \|\| segmentNumber == 0) {
	// This is the first or only segment, so start.
	// Get the URI from the ContentObject including the version.
	var contentUriSpec;
	if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
	var nameWithoutSegmentNumber = new Name
	(contentObject.name.components.slice(0, contentObject.name.components.length - 1));
	contentUriSpec = "ndn:" + nameWithoutSegmentNumber.to_uri();
	}
	else
	contentUriSpec = "ndn:" + contentObject.name.to_uri();

	// Include the search and hash.
	contentUriSpec += this.uriSearchAndHash;

	var contentTypeEtc = getNameContentTypeAndCharset(contentObject.name);
	var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
	this.contentListener.onStart(contentTypeEtc.contentType, contentTypeEtc.contentCharset,
	ioService.newURI(contentUriSpec, this.uriOriginCharset, null));

	if (contentObject.name.getContentDigestValue() != null)
	// We need to compute the content digest.
	this.contentSha256 = new Sha256();
	}

	this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
	if (this.contentSha256 != null)
	this.contentSha256.update(contentObject.content);

	// Check for the special case if the saved content is for the next segment that we need.
	if (this.firstReceivedContentObject != null &&
	this.firstReceivedSegmentNumber == segmentNumber + 1) {
	// Substitute the saved contentObject send its content and keep going.
	contentObject = this.firstReceivedContentObject;
	segmentNumber = segmentNumber + 1;
	// Clear firstReceivedContentObject to save memory.
	this.firstReceivedContentObject = null;

	this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
	if (this.contentSha256 != null)
	this.contentSha256.update(contentObject.content);
	}

	var finalSegmentNumber = null;
	if (contentObject.signedInfo != null && contentObject.signedInfo.finalBlockID != null)
	finalSegmentNumber = DataUtils.bigEndianToUnsignedInt(contentObject.signedInfo.finalBlockID);

	if (!this.uriEndsWithSegmentNumber &&
	segmentNumber != null &&
	(finalSegmentNumber == null \|\| segmentNumber != finalSegmentNumber)) {
	// Make a name for the next segment and get it.
	var segmentNumberPlus1 = DataUtils.nonNegativeIntToBigEndian(segmentNumber + 1);
	// Put a 0 byte in front.
	var nextSegmentNumber = new Uint8Array(segmentNumberPlus1.length + 1);
	nextSegmentNumber.set(segmentNumberPlus1, 1);

	var components = contentObject.name.components.slice
	(0, contentObject.name.components.length - 1);
	components.push(nextSegmentNumber);
	this.ndn.expressInterest(new Name(components), this);
	}
	else {
	// Finished.
	this.contentListener.onStop();
	if (this.contentSha256 != null) {
	var nameContentDigest = contentObject.name.getContentDigestValue();
	if (nameContentDigest != null &&
	!DataUtils.arraysEqual(nameContentDigest, this.contentSha256.finalize()))
	// TODO: How to show the user an error for invalid digest?
	dump("Content does not match digest in name " + contentObject.name.to_uri());
	}
	}

	return Closure.RESULT_OK;
	};

	/*
	* Scan the name from the last component to the first (skipping special name components)
	* for a recognized file name extension, and return an object with properties contentType and charset.
	*/
	function getNameContentTypeAndCharset(name) {
	var iFileName = name.indexOfFileName();
	if (iFileName < 0)
	// Get the default mime type.
	return MimeTypes.getContentTypeAndCharset("");

	return MimeTypes.getContentTypeAndCharset
	(DataUtils.toString(name.components[iFileName]).toLowerCase());
	}

	/*
	* Return true if the last component in the name is a segment number..
	*/
	function endsWithSegmentNumber(name) {
	return name.components != null && name.components.length >= 1 &&
	name.components[name.components.length - 1].length >= 1 &&
	name.components[name.components.length - 1][0] == 0;
	}

	/*
	* Find all search keys starting with "ndn." and set the attribute in template.
	* Return the search string including the starting "?" but with the "ndn." keys removed,
	* or return "" if there are no search terms left.
	*/
	function extractNdnSearch(search, template) {
	if (!(search.length >= 1 && search[0] == '?'))
	return search;

	var terms = search.substr(1).split('&');
	var i = 0;
	while (i < terms.length) {
	var keyValue = terms[i].split('=');
	var key = keyValue[0].trim();
	if (key.substr(0, 4) == "ndn.") {
	if (keyValue.length >= 1) {
	var value = keyValue[1].trim();
	var nonNegativeInt = parseInt(value);

	if (key == "ndn.MinSuffixComponents" && nonNegativeInt >= 0)
	template.minSuffixComponents = nonNegativeInt;
	if (key == "ndn.MaxSuffixComponents" && nonNegativeInt >= 0)
	template.maxSuffixComponents = nonNegativeInt;
	if (key == "ndn.ChildSelector" && nonNegativeInt >= 0)
	template.childSelector = nonNegativeInt;
	if (key == "ndn.AnswerOriginKind" && nonNegativeInt >= 0)
	template.answerOriginKind = nonNegativeInt;
	if (key == "ndn.Scope" && nonNegativeInt >= 0)
	template.scope = nonNegativeInt;
	if (key == "ndn.InterestLifetime" && nonNegativeInt >= 0)
	template.interestLifetime = nonNegativeInt;
	if (key == "ndn.PublisherPublicKeyDigest" && nonNegativeInt >= 0)
	template.publisherPublicKeyDigest = DataUtils.toNumbersFromString(unescape(value));
	if (key == "ndn.Nonce" && nonNegativeInt >= 0)
	template.nonce = DataUtils.toNumbersFromString(unescape(value));
	// TODO: handle Exclude.
	}

	// Remove the "ndn." term and don't advance i.
	terms.splice(i, 1);
	}
	else
	++i;
	}

	if (terms.length == 0)
	return "";
	else
	return "?" + terms.join('&');
	}